KR102092295B1 - Lead-free low temperature calcined glass frit, paste and vacuum glass assembly using the same - Google Patents

Abstract

The present invention relates to a lead-free low temperature fired glass frit, paste and vacuum glass assembly using the same.
The glass frit according to the present invention has a new component system including P ₂ O ₅ , V ₂ O ₅ , TeO ₂ , CuO, ZnO and BaO as the composition ratio specific to the present invention, and replaces the conventional flexible glass composition and has low temperature firing. It is possible, and does not contain an inorganic filler or minimizes the content of the inorganic filler, but the coefficient of thermal expansion with the glass substrate is matched so that peeling or damage does not occur and durability is excellent.

Description

LEAD-FREE LOW TEMPERATURE CALCINED GLASS FRIT, PASTE AND VACUUM GLASS ASSEMBLY USING THE SAME

The present invention relates to a lead-free low temperature fired glass frit, paste and vacuum glass assembly using the same.

In electrical and electronic parts such as glass windows, household appliances, or vacuum insulated double-layer glass panels, display panels, and organic EL display panels, sealing or adhesion is performed by a glass frit containing a glass composition and inorganic ceramic particles. The sealing glass frit is generally applied in the form of a paste, and the glass paste is applied to glass using a screen printing method or a dispenser method, dried and fired to give a sealing function.

Conventionally, a PbOB ₂ O ₃ -based glass composition containing a large amount of lead oxide has been widely applied. This PbOB ₂ O ₃ -based glass composition exhibited good softening fluidity with a softening point of approximately 400-450 ° C and had relatively high chemical stability.

However, in recent years, the design flow in consideration of the environment has been strengthened worldwide, and a safer material is required. In Europe, for example, the European Union Directive (RoHS Directive) on the restriction of the use of certain hazardous substances in electronic and electrical equipment was implemented on 1 July 2006. In the RoHS Directive, a total of six substances including lead are designated as prohibited substances.

Since the PbOB ₂ O ₃ -based glass composition contains a large amount of lead designated as a prohibited substance of the RoHS directive, it has become difficult to use it as a sealing glass paste. Accordingly, development of a novel glass composition containing no lead has been required. In addition, in order to reduce thermal damage and improve productivity of various glass sealing parts or electrical and electronic parts, it is also possible to develop a lead-free glass composition capable of softening flow at a lower temperature than PbOB ₂ O ₃ -based glass composition and having good chemical stability. This is a demand.

P ₂ O ₅ V ₂ O ₅ TeO ₂ -based lead-free glass compositions are known as lead-free glass compositions that can be fired at low temperatures without containing lead in accordance with the demand for lead-free glass compositions.

However, the conventional P ₂ O ₅ V ₂ O ₅ TeO ₂ -based glass composition has a problem in that a tendency to crystallize during firing becomes high, so that good softening fluidity cannot be obtained.

In addition, the conventional P ₂ O ₅ V ₂ O ₅ TeO ₂ -based lead-free glass composition has a problem that peeling or damage may occur due to mismatch of the thermal expansion coefficient with the glass substrate even when firing at a low temperature is possible. There is a problem that the product cost is increased by using a large amount of inorganic filler to lower.

An object of the present invention is to provide a new lead-free low-temperature fired glass frit capable of firing at low temperatures as a lead-free glass composition that replaces the conventional flexible-based glass composition.

In particular, it is an object of the present invention to provide a new lead-free low-temperature fired glass frit having a composition ratio that is not only capable of firing at low temperatures, but also has a low crystallization tendency during low-temperature firing.

In addition, an object of the present invention is to provide a lead-free low-temperature fired glass frit having excellent durability without occurrence of peeling or breakage due to matching of a thermal expansion coefficient with a glass substrate.

In order to provide a new glass frit capable of firing at a low temperature as a lead-free glass composition replacing the conventional flexible glass composition, the glass frit according to the present invention is P ₂ O ₅ 5-25 wt%, V ₂ O ₅ 40 ~ 70 wt%, TeO ₂ 5-25 wt%, CuO 1-5 wt%, ZnO 1-12 wt% and BaO 1-5 wt%.

In addition, in order to provide a glass frit that is not only capable of firing at low temperature, but also has a low crystallization tendency even at low temperature firing, the glass frit according to the present invention is P ₂ O ₅ , The content of V ₂ O ₅ and TeO ₂ may satisfy the following relationship.

[Relationship]

V ₂ O ₅ (% by weight) / P ₂ O ₅ (% by weight) <3.5

P ₂ O ₅ (% by weight) + TeO ₂ (% by weight)> 30

In addition, the glass frit according to the present invention does not contain an inorganic filler or minimizes the content of the inorganic filler, and provides a glass frit having excellent durability without occurrence of peeling or breakage due to matching of a thermal expansion coefficient with a glass substrate. ₂ O ₃ , MnO ₂ , Fe ₂ O ₃ And Ag ₂ O may further include one or more of.

The glass frit according to the present invention has a new component system including P ₂ O ₅ , V ₂ O ₅ , TeO ₂ , CuO, ZnO and BaO as the composition ratio specific to the present invention, and replaces the conventional flexible glass composition and has low temperature firing. There is a possible effect.

In addition, the glass frit according to the present invention is P ₂ O ₅ , V ₂ O ₅ , and TeO ₂ Since it can have an optimum ratio of content, it is possible to fire at a low temperature and has a low crystallization tendency even at low temperature firing.

Furthermore, the glass frit according to the present invention is Bi ₂ O ₃ , MnO ₂ , Fe ₂ O ₃ And Ag ₂ O, and may further include one or more, and the coefficient of thermal expansion (CTE) after firing may be in the range of 80 to 100 x 10 ^-7 / ° C. The coefficient of thermal expansion with the glass substrate is matched, so that peeling or breakage does not occur and durability is excellent.

The above-described objects, features, and advantages will be described in detail below, and accordingly, a person skilled in the art to which the present invention pertains can easily implement the technical spirit of the present invention. In describing the present invention, when it is determined that the detailed description of the known technology related to the present invention may unnecessarily obscure the subject matter of the present invention, the detailed description will be omitted. Hereinafter, a preferred embodiment according to the present invention will be described in detail.

The present invention is not limited to the embodiments disclosed below, but may be implemented in various different forms, and only the present embodiments allow the disclosure of the present invention to be complete and the scope of the invention to those skilled in the art. It is provided to inform.

Hereinafter, the lead-free low-temperature fired glass frit, paste, and vacuum glass assembly using the same according to the present invention will be described in detail.

<Lead free low temperature firing glass frit>

The glass frit used as a sealing material generally has low fluidity at a low temperature when the physical properties such as a glass transition point and a softening point are low, but if the temperature is too low, the tendency to crystallize increases according to the opposite supply, so May deteriorate the liquidity.

In addition, when the sealing process is applied at a high temperature, the glass used in home appliances or electronic products has a problem of glass breakage or an increase in process cost, and thus the sealing process needs to be applied at 400 ° C. or lower. Therefore, the glass frit sealing material used in the sealing process should be capable of firing at low temperatures. In addition, it must be able to fire at low temperatures and at the same time satisfy the appropriate softening fluidity.

Accordingly, the present inventors have completed a new glass frit that is capable of firing at low temperature and has low crystallization tendency.

The glass frit according to the present invention is P ₂ O ₅ 5-25 wt%, V ₂ O ₅ 40-70 wt%, TeO ₂ 5-25 wt%, CuO 1-5 wt%, ZnO 1-12 wt% and BaO 1 to 5% by weight.

P ₂ O ₅ is contained in the range of 5 to 25% by weight to lower the firing temperature of the glass frit and control the flowability. When the P ₂ O ₅ exceeds 25% by weight, it is easy to fire the glass frit, and there is a problem that the fluidity is lowered. If P ₂ O ₅ is less than 5% by weight, a thermal frit coefficient of the glass frit increases and a problem that adhesive strength with the glass substrate decreases may occur.

V ₂ O ₅ has the effect of lowering the softening point while increasing the durability of the glass frit and is contained in the range of 40 to 70% by weight in the glass frit. When the V ₂ O ₅ exceeds 70% by weight, there is a problem that the firing of the glass frit tends to be difficult. When V ₂ O ₅ is less than 40% by weight, the effect of lowering the softening point of the glass frit is difficult to be sufficiently exhibited, and also the durability of the glass frit may occur.

TeO ₂ has an effect of increasing the fluidity of the glass frit and is contained in the range of 5 to 25% by weight in the glass frit. If the TeO ₂ exceeds 25% by weight, it may be difficult to sufficiently lower the softening point, and it may not be fired. If TeO ₂ is less than 5% by weight, a problem in that vitrification of the glass frit may be difficult depending on a balance relationship with other components.

CuO is contained in the range of 1 to 5% by weight to match the thermal expansion coefficient of the glass frit and satisfy the durability. When the CuO exceeds 5% by weight, a problem may arise that the fluidity of the glass frit is lowered. If CuO is less than 1% by weight, the required thermal expansion coefficient of the glass frit may not be obtained.

ZnO is contained in the range of 1 to 12% by weight to match the coefficient of thermal expansion of the glass frit and satisfy durability. When the ZnO exceeds 12% by weight, the fluidity of the glass frit decreases, and adhesion to the glass substrate may be a problem. If ZnO is less than 1% by weight, the required thermal expansion coefficient of the glass frit may not be obtained.

BaO is contained in the range of 1 to 5% by weight to match the thermal expansion coefficient of the glass frit and satisfy the durability. When the CuO exceeds 5% by weight, a problem may arise that the fluidity of the glass frit is lowered. If CuO is less than 1% by weight, the required thermal expansion coefficient of the glass frit may not be obtained.

In addition, the glass frit according to the present invention is additionally Bi₂O₃, MnO₂, Fe₂O₃ And Ag₂It may further include one or more of O, preferably Bi to increase the durability of the glass frit and lower the tendency to crystallize₂O₃, MnO₂, Fe₂O₃ And Ag₂One or more of O may be included in 25% by weight or less. Bi₂O₃, MnO₂, Fe₂O₃ And Ag₂If one or more of O exceeds 25% by weight, the thermal expansion coefficient may be lowered, but sealing performance may be deteriorated.

In addition, included in the glass frit according to the present invention, P ₂ O ₅ , The content of V ₂ O ₅ and TeO ₂ is preferably contained in order to satisfy the following relationship in terms of plastic stability related to crystallization tendency.

 [Relationship]

V ₂ O ₅ (% by weight) / P ₂ O ₅ (% by weight) <3.5

P ₂ O ₅ (% by weight) + TeO ₂ (% by weight)> 30

As the content of V ₂ O ₅ increases, the glass transition point of the glass frit may be lowered to lower the temperature at which sealing is possible, but at the same time, it is desirable to have an optimal ratio in the relationship between P ₂ O ₅ and TeO ₂ because the crystallization tendency of the glass frit increases. Do. Accordingly, it is very preferable that the glass frit according to the present invention has a composition ratio that satisfies all the above relations.

In addition, the glass frit according to the present invention preferably has a thermal expansion coefficient of 80 to 100 x 10 ^-7 / ° C, particularly in terms of matching the thermal expansion coefficient with a glass substrate, and preferably has a softening point of 400 ° C or less. Since the thermal window coefficient falls within the range of 80 to 100 x 10 ^-7 / ° C, the glass frit according to the present invention can reduce the occurrence of deterioration in adhesion, thereby improving sealing reliability. In addition, the glass frit according to the present invention has a softening point of 400 ° C. or less, so that the sealing process of the glass substrate can be performed at a low temperature of 400 ° C. or less.

In addition, the glass frit according to the present invention has an advantageous effect of having a low thermal expansion coefficient and lowering softening point even if it does not contain an inorganic filler or is included in a minimum content by having the above-mentioned component system and composition ratio.

If necessary, the glass frit according to the present invention may include a small amount of an inorganic filler. Inorganic filler is a crystalline inorganic particle having a low coefficient of thermal expansion, specifically, one of zirconium phosphate, zirconium phosphate tungstate, zirconium, Li ₂ O-Al ₂ O ₃ -SiO ₂ , beta-eucryptite and zirconium tungstate The above can be used.

<Glass frit paste>

Next, the glass frit paste according to the present invention includes 100 parts by weight of the aforementioned glass frit and 10 to 100 parts by weight of the organic vehicle.

If the organic vehicle is less than 20 parts by weight or more than 100 parts by weight, the viscosity of the paste is too high or too low, so the application process may be difficult.

The organic vehicle may include an organic solvent and an organic binder. The organic solvent may be a solvent such as α- terpineol or butyl carbitol, and the organic binder may be ethyl cellulose, but is not limited thereto.

<Vacuum glass assembly>

Vacuum glass assembly means an assembly that includes two or more glass substrates and is maintained in a vacuum between the two or more glass substrates. The vacuum glass assembly can also be used in household appliances such as refrigerators, microwave ovens and washing machines, or in electronic components of many electronic devices.

The glass frit according to the present invention can be used as a sealing material in the vacuum glass assembly.

When the glass frit paste according to the present invention is applied as a sealing material, a sealing process is possible at less than 400 ° C. corresponding to a low temperature. Therefore, when the glass frit paste according to the present invention is applied as a sealing material, the risk of breakage of the glass substrate is lowered and it has an advantageous effect of lowering the process cost.

The vacuum glass assembly according to the present invention comprises: a first glass substrate; A second glass substrate spaced apart from the first glass substrate; And a sealing material arranged along the edges of the first or second glass substrate, sealing the first and second glass substrates and sealing the space between the first and second glasses. The paste according to claim is applied and fired to form.

The first glass substrate and the second glass substrate of the present invention may be selected according to the needs of the article to which the vacuum glass assembly is applied, and is not particularly limited.

In addition, the glass frit paste mentioned above is used as a sealing material.

Hereinafter, a specific aspect of the present invention will be described with reference to examples.

<Example>

<Production of glass frit>

Glass frits having a composition ratio shown in Table 1 below were prepared. The raw materials of each component were thoroughly mixed for 3 hours in a V-mixer. Here, as the raw material for BaO, NH ₄ H ₂ PO ₄ was used as the raw material for BaCO ₃ and P ₂ O ₅ , and the rest of the components were the same as those in Table 1. The mixed material was sufficiently melted for 1 hour at 800 to 1000 ° C, and quenched in a quenching roller to obtain a glass cullet.

After controlling the initial particle size of the glass cullet obtained by the above process with a ball mill, pulverized for about 1 hour and then passed through a 325 mesh sieve (ASTM C285-88) to control the particle size so that the un passed glass powder remains within 1 g. .

[Table 1]

<Paste production>

After the α-terpineol (α-terpineol) and ethyl cellulose (Ethyl cellulose) were mixed in an appropriate ratio to prepare an organic vehicle, the glass frit prepared as above was mixed in an appropriate ratio to prepare a paste. A three roll mill was used for uniform mixing.

<Vacuum glass assembly specimen manufacturing>

Two glass substrates were prepared, and pastes according to Examples 1 and 2 and Comparative Examples 1 and 2 were applied to the outer portions of each glass substrate to prepare a total of four glass assembly specimens. Vacuum exhaust and sealing processes were performed at 400 ° C for these glass assemblies. Accordingly, a total of four glass assembly specimens were completed.

<Experimental Example>

The glass frits, pastes, and specimens prepared in Examples and Comparative Examples were measured as follows and the results are shown in Table 2.

1. Glass transition temperature (Tg)

The glass transition point was measured using a TMA equipment (TMA-Q400 TA instrument) at a heating rate of 10 ° C / min.

2. Thermal expansion coefficient (CTE (ⅹ10 ^-7 / ℃))

The thermal expansion coefficient was measured using a TMA equipment (TMA-Q400 TA instrument) at a heating rate of 10 ° C / min.

3. Haf Ball temperature

When a glass frit was present in powder form at a heating rate of 10 ° C / min using a high-temperature microscope, it was observed when the maximum shrinkage and half-ball shape occurred by temperature.

4. Water resistance

After the specimen was placed in a distilled water bath at 90 ° C. and maintained for 48 hours, the color change and weight change of the distilled water were observed. The weight after immersion was measured, and the increase / decrease rate of the weight was less than 1%, and the case of 1% or more was denoted by Х.

5. Plastic stability

The glass frit powder was press-molded into a metal mold and heated to 600 ° C. at 10 ° C./min to observe crystallization after firing. ◎: Crystallization does not occur and gloss is very good. ○: Crystallization does not occur and gloss is good. Х: Crystallization occurs and there is no luster.

[Table 2]

As described in Table 2, the embodiment according to the present invention is not only capable of firing at low temperatures because the half ball temperature is 400 ° C. or less, the thermal expansion coefficient is 90 to 100, so it is matched with the glass substrate, and water resistance, It can be seen that the plastic stability is excellent.

The comparative examples were for a glass frit having a P ₂ O ₅ V ₂ O ₅ TeO ₂ component system, and it was confirmed that the water resistance and the plastic stability were unsatisfactory because the softening point was not high and sealing was not properly performed compared to the example.

As described above, the present invention has been described, but it is obvious that the present invention is not limited by the embodiments disclosed herein, and that various modifications can be made by those skilled in the art within the scope of the technical idea of the present invention. In addition, although the operation and effect according to the configuration of the present invention is not explicitly described while explaining the embodiments of the present invention, it is natural that the predictable effect by the configuration should also be recognized.

Claims (7)

P ₂ O ₅ 5-25% by weight,
V ₂ O ₅ 40-70 wt%,
TeO ₂ 5-25% by weight,
CuO 1-5% by weight,
ZnO 1-12 wt% and
BaO containing 1 to 5% by weight,
Ag ₂ O further comprises,
Does not contain inorganic fillers,
Glass frit.
According to claim 1,
P ₂ O ₅ , Glass frit characterized in that the content of V ₂ O ₅ and TeO ₂ satisfies the following relationship.

[Relationship]
V ₂ O ₅ (% by weight) / P ₂ O ₅ (% by weight) <3.5
P ₂ O ₅ (% by weight) + TeO ₂ (% by weight)> 30
According to claim 1,
Bi ₂ O ₃ , MnO ₂ And Fe ₂ O ₃ Glass frit characterized in that it further comprises at least one.
According to claim 1,
The glass frit
Glass frit characterized in that the coefficient of thermal expansion (CTE) after firing is in the range of 80 to 100 x 10 ^-7 / ° C.
According to claim 1,
A glass frit characterized in that the softening point is 400 ° C or less.
A glass frit according to any one of claims 1 to 5 and 100 parts by weight of an organic vehicle, comprising 10 to 100 parts by weight
Glass frit paste.
A first glass substrate;
A second glass substrate spaced apart from the first glass substrate; And
Includes; is arranged along the edge of the first or second glass substrate, sealing material for adhering the first and second glass substrate and sealing the space between the first and second glass;
The sealing material is formed by applying and firing the paste according to claim 6
Vacuum glass assembly.